<template>
  <div>
    <el-breadcrumb class="app-breadcrumb" separator="/">
      <transition-group name="breadcrumb">
        <el-breadcrumb-item v-for="(item, index) in levelList" :key="item.path">
          <span
            v-if="
              item.redirect === 'undefined' || index == levelList.length - 1
            "
            class="no-redirect"
            >{{ item.meta.title }}</span
          >
          <a v-else @click.prevent="handleLink(item)">{{ item.meta.title }}</a>
        </el-breadcrumb-item>
      </transition-group>
    </el-breadcrumb>
  </div>
</template>
<script>
// import pathToRegexp from 'path-to-regexp'

export default {
  data() {
    return {
      levelList: null,
    };
  },
  watch: {
    $route() {
      this.getBreadcrumb();
    },
  },
  created() {
    this.getBreadcrumb();
  },
  methods: {
    getBreadcrumb() {
      // only show routes with meta.title
      let matched = this.$route.matched.filter(
        (item) => item.meta && item.meta.title
      );
      const first = matched[0];
      console.log("first", first);
      if (!this.isDashboard(first)) {
        // concat把两个拼接在一起
        matched = [{ path: "/", meta: { title: "首页" } }].concat(matched);
      }

      this.levelList = matched;
    },
    isDashboard(route) {
      const name = route && route.name;
      if (!name) {
        return false;
      }
      return (
        name.trim().toLocaleLowerCase() === "Dashboard".toLocaleLowerCase()
      );
    },
    // pathCompile(path) {
    //   // To solve this problem https://github.com/PanJiaChen/vue-element-admin/issues/561
    //   const { params } = this.$route
    //   console.log(params)
    //   var toPath = pathToRegexp.compile(path)
    //   return toPath(params)
    // },
    handleLink(item) {
      const { redirect, path } = item;
      if (redirect) {
        //  vue-router 实例上的 push 方法返回的是 promise 对象，所以传入的参数期望有一个成功和失败的回调，如果省略不写则会报错。
        //解决方案一：每次使用 push 方法时带上两个回调函数：
        this.$router.push(
          redirect,
          () => {},
          () => {}
        );
        return;
      }
      // this.$router.push(this.pathCompile(path))
      this.$router.push(path);
    },
  },
};
</script>
<style lang="scss" scoped>
.app-breadcrumb.el-breadcrumb {
  display: inline-block;
  font-size: 14px;
  line-height: 60px;
  margin-left: 8px;

  .no-redirect {
    color: #97a8be;
    cursor: text;
  }
}
</style>
